Rieder, Florian

INTRODUCTION: Computed tomography enterography (CTE) is a noninvasive cross-sectional imaging modality routinely used for diagnosis of Crohn's disease (CD) strictures. However, CTE is limited in individually defining the severity of inflammation, fibrosis, or smooth muscle hyperplasia/hypertrophy (SMH) within such strictures. We developed and internally validated a radiomics-based machine learning model for separately characterizing the degree of histopathological inflammation, fibrosis, and SMH in CD strictures and compared it with centrally read visual radiologist scoring of CTE. METHODS: This single-center, cross-sectional study included 100 patients with CD (n = 66 for discovery; n = 34 for validation) with terminal ileal strictures confirmed on diagnostic CTE within 15 weeks of intestinal resection. Histopathological specimens were scored for inflammation, fibrosis, and SMH and spatially linked with corresponding pre-surgical CTE sequences. Annotated stricture regions on CTE were scored visually by radiologists as well as underwent three-dimensional radiomics-based machine-learning analysis; both evaluated against histopathology scoring. RESULTS: Three distinct sets of radiomic features capturing textural heterogeneity within strictures were separately linked with severe inflammation, fibrosis, and SMH across both discovery (accuracy = 0.74, 0.71, 0.71, respectively) and validation (accuracy = 0.74, 0.68, 0.68, respectively) cohorts. Radiologist visual scoring was limited, with accuracy of 0.51 for identifying severe inflammation, 0.48 for severe fibrosis, and 0.58 for severe SMH. Augmenting radiologist scoring with radiomic features yielded improved performance in identifying severe inflammation, fibrosis, or SMH compared to radiologist scoring alone. DISCUSSION: Radiomic features of CD strictures on CTE can identify severe histopathological fibrosis, inflammation, and smooth muscle hyperplasia and perform better than radiologist visual scoring in stricture characterization.

Abstract Background & Aims Stricturing Crohn’s disease (CD) is a significant problem, and no selective anti-fibrotic therapies are available. Anti-inflammatory approaches are the mainstay of medical treatment. However, data on the efficacy of ustekinumab (USTE) in ileal stricturing CD are lacking. Our aim was to assess its efficacy in this setting. Methods We performed an international multicenter observational cohort study evaluating adult CD patients who received USTE within 6 months of imaging-confirmed symptomatic stricturing small bowel disease. Outcomes were rates of endoscopic balloon dilation (EBD), surgery, intervention (defined as the composite need for EBD or surgery), recurrent obstructive symptoms, and USTE persistence. Results Fifty-seven patients were included (51% female, median age 43 years). Median follow-up was 17 months. Intervention rates were 35%, 45%, and 69% of patients, at 12, 24, and 48 months, respectively. USTE persistence was 78%, 76%, and 52% at 12, 24, and 48 months. Estimated obstructive symptoms rates were 31% and 49% at 12 and 24 months, respectively. EBD within 6 months prior to starting USTE was associated with an increased risk of intervention. Increased bowel wall thickness on imaging, prior biologic use, and obstructive symptom duration were associated with USTE discontinuation. Occurrence of obstructive symptoms during treatment was associated with prior biologic use, EBD within 6 months of starting USTE, and a lower BMI. Conclusions USTE appears to be an appropriate medical option in biologic-experienced CD patients with ileal strictures. Further prospective data are needed to better define outcomes and predictors of response in this setting.

This consensus by the Society of Abdominal Radiology Inflammatory Bowel Disease Disease Focused Panel provides an updated imaging-based definition of small bowel Crohn disease stricture for CT and MR enterography.

Abstract Background and Aims Over 10% of patients with Crohn’s disease require permanent ileostomy. We aimed to summarize the existing data on diagnosis, definitions of recurrence, and management of Crohn’s disease patients with permanent ileostomy. Methods MEDLINE, Embase, and CENTRAL databases were searched from inception to February 6, 2024. Randomized controlled trials, cohort and cross-sectional studies, and case series of more than 5 patients reporting on postoperative recurrence or the need for surgery in patients with Crohn’s disease and permanent ileostomy were included. Search results were independently screened, and full text of all titles meeting eligibility criteria was obtained. Outcomes of interest included diagnostic techniques, recurrence definitions, and management approaches. We estimated pooled rates (with 95% confidence interval [CI]) of recurrence. Results Thirty cohort studies including 2055 Crohn’s patients with permanent ileostomy were included (53% female, median age at the time of ileostomy creation 32 years, the most common reason for ileostomy was refractory disease). The postoperative recurrence rate was 27% (95% CI, 21.3–33.3, 26 studies, 451/1805 patients). Modalities for diagnosis of Crohn’s disease recurrence were symptoms (15 studies), endoscopy (4 studies), histology from endoscopic biopsies (2 studies), imaging (5 studies), and surgery (22 studies). The reported definitions of recurrence for each modality were heterogeneous. Conclusions There is a lack of standardized monitoring tools and criteria for diagnosing recurrence in patients with Crohn’s disease and permanent ileostomy. The results of this systematic review will form the basis of a global expert recommendation exercise focused on developing management standards and trial endpoints for this condition.

Abstract Background Inflammatory bowel disease (IBD)–associated peripheral spondyloarthritis (pSpA) decreases quality of life and remains poorly understood. Given the prevalence of this condition and its negative impact, it is surprising that evidence-based disease definitions and diagnostic strategies are lacking. This systematic review summarizes available data to facilitate development and validation of diagnostics, patient-reported outcomes, and imaging indices specific to this condition. Methods A literature search was conducted. Consensus or classification criteria, case series, cross-sectional studies, cohort studies, and randomized controlled trials related to diagnosis were included. Results A total of 44 studies reporting data on approximately 1500 patients with pSpA were eligible for analysis. Data quality across studies was only graded as fair to good. Due to large heterogeneity, meta-analysis was not possible. The majority of studies incorporated patient-reported outcomes and a physical examination. A total of 13 studies proposed or validated screening tools, consensus, classification, or consensus criteria. A total of 28 studies assessed the role of laboratory tests, none of which were considered sufficiently accurate for use in diagnosis. A total of 17 studies assessed the role of imaging, with the available literature insufficient to fully endorse any imaging modality as a robust diagnostic tool. Conclusions This review highlights existing inconsistency and lack of a clear diagnostic approach for IBD-associated pSpA. Given the absence of an evidence-based approach, a combination of existing criteria and physician assessment should be utilized. To address this issue comprehensively, our future efforts will be directed toward pursuit of a multidisciplinary approach aimed at standardizing evaluation and diagnosis of IBD-associated pSpA.

Abstract Background and Aims Non-invasive cross-sectional imaging via magnetic resonance enterography [MRE] offers excellent accuracy for the diagnosis of stricturing complications in Crohn’s disease [CD] but is limited in determining the degrees of fibrosis and inflammation within a stricture. We developed and validated a radiomics-based machine-learning model for separately characterizing the degree of histopathological inflammation and fibrosis in CD strictures and compared it to centrally read visual radiologist scoring of MRE. Methods This single-centre, cross-sectional study included 51 CD patients [n = 34 for discovery; n = 17 for validation] with terminal ileal strictures confirmed on diagnostic MRE within 15 weeks of resection. Histopathological specimens were scored for inflammation and fibrosis and spatially linked with corresponding pre-surgical MRE sequences. Annotated stricture regions on MRE were scored visually by radiologists as well as underwent 3D radiomics-based machine learning analysis; both were evaluated against histopathology. Results Two distinct sets of radiomic features capturing textural heterogeneity within strictures were linked with each of severe inflammation or severe fibrosis across both the discovery (area under the curve [AUC = 0.69, 0.83] and validation [AUC = 0.67, 0.78] cohorts. Radiologist visual scoring had an AUC = 0.67 for identifying severe inflammation and AUC = 0.35 for severe fibrosis. Use of combined radiomics and radiologist scoring robustly augmented identification of severe inflammation [AUC = 0.79] and modestly improved assessment of severe fibrosis [AUC = 0.79 for severe fibrosis] over individual approaches. Conclusions Radiomic features of CD strictures on MRE can accurately identify severe histopathological inflammation and severe histopathological fibrosis, as well as augment performance of the radiologist visual scoring in stricture characterization.

Summary Background Stricturing Crohn's disease (CD) occurs most commonly in the terminal ileum and poses a clinical problem. Cross‐sectional imaging modalities such as intestinal ultrasound (IUS), computed tomography enterography (CTE), and magnetic resonance enterography (MRE) allow for assessment of the entire bowel wall and associated peri‐enteric findings. Radiologic definitions of strictures have been developed for CTE and MRE; their reliability and responsiveness are being evaluated in index development programs. A comprehensive assessment strategy for strictures using IUS is needed. Aims To provide a detailed summary of definitions, diagnosis and monitoring of strictures on IUS as well as technical aspects of image acquisition. Methods We searched four databases up to 6 January 2024. Two‐stage screening was done in duplicate. We assessed risk of bias using QUADAS‐2. Results There were 56 studies eligible for inclusion. Definitions for strictures on IUS are heterogeneous, but the overall accuracy for diagnosis of strictures is high. The capability of IUS for characterising inflammation versus fibrosis in strictures is not accurate enough to be used in clinical practice or trials. We summarise definitions for improvement of strictures on IUS, and discuss parameters for image acquisition and standardisation. Conclusions This systematic review is the first step for a structured program to develop a stricture IUS index for CD.